PDFvcon was released here a few days ago on sourceforge.net. It is nothing more than a GUI interface to call Ghostscript to accomplish the task. But, it sure is easier to use a GUI than to remember the command line command.

If you have need to convert PDF document versions, such as your old software only deals with version 1.5, but most of the PDF documents you are getting these days is in version 1.6. Then this is for you. Make that old software continue to work and keep your money in your pocket.